Sometimes we birders may count 100 or so common goldeneyes in with some mallards wintering at open water areas such as below the Coon Rapids Dam or other open spots on the Mississippi River.

Goldeneyes are often called "whistlers" owing to the sound their wings make in flight.

These midsize, 2-pound ducks get their name from their yellow eyes, but the males possess even more colorful features. A male has a green head, white cheek patch, and a great amount of white showing on his black-and-white body. Females are gray with brown heads and white collars.

The steam fog from waters on winter days can make viewing difficult, but the ducks dive and feed in seeming comfort. The water temperatures are in the low 30s, warmer than the air, and the ducks' well-insulated feathers keep their wet bodies from losing too much heat.

Many of the goldeneyes from Minnesota will winter as far south as the Gulf of Mexico, but some stay here and especially like the Mississippi River and Lake Superior. They return to the lakes in the northeastern and north-central regions of the state when summer arrives, and nest in tree cavities of the boreal forest. Nesting boxes are frequently put up for goldeneyes.

Expert at diving, common goldeneyes may remain underwater for about 20 seconds and dive to a depth of about 20 feet, but usually feed in water less than 10 feet deep. Their food consists of aquatic insects and plants, but they also eat crayfish and snails. In saltwater areas they add mussels and several types of crabs to their diet.

Jim Gilbert's Nature Notes are heard on WCCO Radio at 7:15 a.m. Sundays. His observations have been part of the Minnesota Weatherguide Environment Calendars since 1977, and he is the author of five books on nature in Minnesota. He taught and worked as a naturalist for 50 years.